Schengen visa 90/180 rule confusion

I have a type d national visa (multi entry) and work permit of Poland for 180 days.I had a transit though Germany -Munich so first port of entry was Munich so stamping was done in Munich. No additional immigration/stamping at Poland. I suspect if the 90 days count has started. Or will the stamp date be just treated just for transit purpose as I had another connecting flight to Poland though no visa entry date stamp for Poland .

A type D Schengen visa is equivalent to a regular residential permit. With a D type Schengen visa, a traveller is allowed to visit other Schengen countries for up to 90 days within a 180 day period. This period does not include the time you spend in Poland for this case, of course. Note that when travelling to ther Schengen countries, you must carry your passport or equivalent travel documents, be able to document the purpose of your visit, document your ability to finance the trip, have valid medical travel insurance, be of no danger to national security or public health, and not have been specifically expelled from the country you are traveling to. There is no immigration control on the borders between Schengen states, you do not need to worry about the stamp. Hope this helps.